Radio Frequency Treatment for Controlling Cigarette Beetle, <I> Lasioderma serricorne </I> (Fabricius)

Abstract

Using of radio frequency (RF) for controlling cigarette beetle, Lasioderma serricorne (Fabricius) (Coleoptera: Anobiidae), an important pest of stored-product insect particular in green leaf tobacco, was conducted at Postharvest Technology Research Institute, Chiang Mai University, Chiang Mai, Thailand. The study was composed of 2 part in the first part was the tolerance of cigarette beetle to RF using egg, larval, pupal and adult stages exposed to RF at 27.12 MHz with a power of 420 watt for 60 seconds. It was found that adult stage of cigarette beetle was the most tolerance to RF with the mortality at 55.00 ±0.17 percent, followed by pupal, larval and egg stage with the mortality at 81.88 ±0.14, 97.50 ±0.11 and 99.37 ±0.04 percent, respectively. The second part was the tolerance of cigarette beetle to various periods of RF exposion. The pressured Burley green leaf tobacco blened with cigarette beetle adult were put in laminate bag and then exposed to RF with the power of  420 watt for 30, 60, 90, 120, 150 and 180 seconds which corresponding to temperature of 34.77, 46.23, 58.27, 60.45, 73.40 and 104.18 ^oC respectively. The results showed that the levels of temperature was increased when period of exposion was longer. The adult cigarette beetle completely died at 180 seconds of 420-RF treatment corresponding to 104.18 ^oC. Moisture content of RF treatment on green leaf tobacco in laminate bag (10.58%) was not significantly different from the untreated control (10.59%). The orange Burley green leaf tobacco (B2F grade) was slightly changed to dark orange. Nicotine content of RF-treated tobacco (4.13%) was significantly different from untreated control (3.18%) while the reducing sugar contents were not consistency. Based on the Burley green leaf tobacco standard, the chemical and physical properties of RF-treated tobacco were remained.